Long-persistent luminescence emitter and long-persistent luminescent device

Abstract

A long-persistent luminescence emitter containing a polymer that contains, relative to the total molar amount of an electron donor structural unit and an electron acceptor structural unit therein, 70 mol % or more of an electron donor structural unit and less than 30 mol % of an electron acceptor structural unit, or containing a polymer that contains, relative to the total molar amount of an electron donor structural unit and an electron acceptor structural unit therein. 70 mol % or more of an electron acceptor structural unit and less than 30 mol % of an electron donor structural unit. The emission decay after stopping light irradiation to the emitter is power law decay.

The invention claimed is: 
     
         1 . A long-persistent luminescence emitter that emits light for 0.1 seconds or longer after stopping light irradiation of the long-persistent luminescence emitter;
 wherein the long-persistent luminescence emitter contains a polymer that contains, relative to a total molar amount of an electron donor structural unit and an electron acceptor structural unit therein, 70 mol % or more of an electron donor structural unit and less than 30 mol % of an electron acceptor structural unit, or contains a polymer that contains, relative to a total molar amount of an electron donor structural unit and an electron acceptor structural unit therein, 70 mol % or more of an electron acceptor structural unit and less than 30 mol % of an electron donor structural unit, wherein:   an energy level of HOMO of the electron donor structural unit is higher than that of the electron acceptor structural unit,   an electron transfer from the electron donor structural unit to the electron acceptor structural unit occurs by light irradiation of the long-persistent luminescence emitter, and   an emission decay after stopping light irradiation of the long-persistent luminescence emitter is a power law decay.   
     
     
         2 . The long-persistent luminescence emitter according to  claim 1 , wherein the polymer is a random copolymer. 
     
     
         3 . The long-persistent luminescence emitter according to  claim 1 , wherein the electron donor structural unit contains a diarylamine structure. 
     
     
         4 . The long-persistent luminescence emitter according to  claim 1 , wherein the electron donor structural unit contains a substituted or unsubstituted carbazolyl group. 
     
     
         5 . The long-persistent luminescence emitter according to  claim 1 , wherein the electron acceptor structural unit contains a π-electron-deficient aromatic heterocycle. 
     
     
         6 . The long-persistent luminescence emitter according to  claim 1 , wherein the electron acceptor structural unit contains a pyrylium ring. 
     
     
         7 . The long-persistent luminescence emitter according to  claim 1 , wherein the polymer contains 70 mol % or more of the electron donor structural unit and less than 30 mol % of the electron acceptor structural unit relative to the total molar amount thereof, and further contains a hole trapping structural unit. 
     
     
         8 . The long-persistent luminescence emitter according to  claim 1 , wherein the polymer contains 70 mol % or more of the electron acceptor structural unit and less than 30 mol % of the electron donor structural unit relative to the total molar amount thereof, and further contains an electron trapping structural unit. 
     
     
         9 . A long-persistent luminescent device having the long-persistent luminescence emitter of  claim 1  on a support.